We identified 11870 records. The PRISMA flow diagram is presented in
Figuare 1. A total of 11 studies with data from 771 participants were
eligible for inclusion.The additional texts included secondary analyses,
abstracts, trial registries, and protocol papers.
Study description
10 of the studies were RCTs, and 1 was a crossover RCT (Greene &
Petruzzello, 2022).The specific intervention and comparison groups for
the 11 eligible studies (13 comparisons) are presented in Table 1.
| Bryant2023 |
exercise + therapy |
attention control + therapy |
aerobic |
exposure therapy |
NA |
static stretching |
| Voorendonk2023 |
exercise + therapy |
attention control + therapy |
mixed |
PE + EMDR |
NA |
guided (creative) tasks |
| Nordbrandt2020 |
exercise + TAU |
TAU |
mixed |
NA |
combination: medical doctor, 1 to 2 sessions with
social worker / psychologist |
NA |
| Rosenbaum2014 |
exercise + TAU |
TAU |
mixed |
NA |
combination: individual and group psychotherapy,
pharmacotherapy |
NA |
| Young-McCaughan2022b |
exercise + therapy |
therapy only |
aerobic |
imaginal exposure |
NA |
NA |
| Huseth2022 |
exercise only |
WLC |
aerobic |
NA |
NA |
NA |
| Young-McCaughan2022a |
exercise only |
TAU |
aerobic |
NA |
self-care intervention delivering educational and
instructional information |
NA |
| Whitworth2019a |
exercise only |
attention control |
anaerobic |
NA |
NA |
videos on various educational topics (excluding
exercise and mental health). |
| Whitworth2019b |
exercise only |
attention control |
anaerobic |
NA |
NA |
videos on various educational topics (excluding
exercise and mental health). |
| Crombie2021 |
exercise + extinction learning |
attention control + extinction learning |
aerobic |
extinction learning |
NA |
NA |
| Greene2022a |
exercise only |
attention control |
mixed |
NA |
NA |
remained sedentary in the lab |
| Greene2022b |
exercise only |
attention control |
aerobic |
NA |
NA |
remained sedentary in the lab |
| Powers2015 |
exercise + therapy |
therapy alone |
aerobic |
prolonged exposure |
NA |
NA |
Aerobic = physical performance behaviour pattern that increases
heart rate and respiration while using large muscle groups repetitively
and rhythmically; anaerobic = physical performance behaviour pattern
that is performed in short intense bursts with limited oxygen intake;
mixed = combination of aerobic and anaerobic exercise. TAU = treatment
as usual; WLC = waiting list control.
Table 1: Specific interventions for all the included
studies
8 of the 11 studies were included in the meta-analyses (Bryant et
al., 2023; Huseth, 2021; Nordbrandt et al., 2020; Rosenbaum et al.,
2015; Voorendonk et al., 2023; Whitworth et al., 2019a; Whitworth et
al., 2019b; Young-McCaughan et al., 2022). Meta-analysis was not
feasible for 3 of the 11 studies (Crombie et al., 2021a; Greene &
Petruzzello, 2022; Powers et al., 2015). Three of the studies provided
follow-up PTSD outcome data which were insufficient for synthesis, which
were synthesized descriptively without meta-analysis (Crombie et al.,
2021a; Greene & Petruzzello, 2022; Powers et al., 2015). Three
studies examined putative mediators which was not sufficient to carry
out a meta-analysis (Crombie et al., 2021a; Powers et al., 2015;
Whitworth et al., 2019a).
Study characteristics of the 8 studies included in the meta-analysis
are are presented in Table 2. From these 8 studies, there were 9
eligible comparisons. One study presented findings from two independent
comparisons, including a total of four distinct intervention groups
(Young-McCaughan et al., 2022). One of the first authors published
findings from two different but methodologically similar trials in the
same year (Whitworth et al., 2019a; Whitworth et al., 2019b).
| Bryant2023 |
2023 |
130 |
exercise + therapy |
attention control + therapy |
CAPS-IV |
yes |
aerobic |
high |
10 weeks |
34 weeks |
NA |
Australia |
| Voorendonk2023 |
2023 |
120 |
exercise + therapy |
attention control + therapy |
PCL-5 |
yes |
mixed |
moderate |
12 weeks |
26 weeks |
NA |
Netherland |
| Nordbrandt2020 |
2020 |
224 |
exercise + TAU |
TAU |
HTQ |
yes |
mixed |
moderate |
20 weeks |
NA |
NA |
Denmark |
| Rosenbaum2014 |
2014 |
81 |
exercise + TAU |
TAU |
PCL-4 |
yes |
mixed |
high |
12 weeks |
NA |
NA |
Australia |
| Young-McCaughan2022b |
2022 |
36 |
exercise + therapy |
therapy only |
PCL-5 |
no |
aerobic |
high |
8 weeks |
12 weeks |
32 weeks |
USA |
| Huseth2022 |
2022 |
21 |
exercise only |
WLC |
PCL-5 |
no |
aerobic |
moderate |
8 weeks |
NA |
NA |
USA |
| Young-McCaughan2022a |
2022 |
36 |
exercise only |
TAU |
PCL-5 |
no |
aerobic |
high |
8 weeks |
12 weeks |
32 weeks |
USA |
| Whitworth2019a |
2018 |
30 |
exercise only |
attention control |
PDS-5 |
no |
anerobic |
high |
3 weeks |
NA |
NA |
USA |
| Whitworth2019b |
2019 |
22 |
exercise only |
attention control |
PDS-5 |
no |
anerobic |
high |
3 weeks |
NA |
NA |
USA |
TAU = treatment as usual; WLC = waiting list control; CAPS-IV =
Clinician-Administered PTSD Scale - 4th edition; PCL-4 = PTSD Checklist
- version 4; PCL-5 = PTSD Checklist - version 5; PDS-5 = Posttraumatic
Diagnostic Scale – version 5; HTQ = Harvard Trauma Questionnaire;
Aerobic exercise = physical performance behaviour pattern that increases
heart rate and respiration while using large muscle groups repetitively
and rhythmically; anaerobic exercise = physical performance behaviour
pattern that is performed in short intense bursts with limited oxygen
intake; mixed exercise = combination of aerobic and anaerobic exercise;
USA = United States of America.
Table 2: Study characteristics of the 8 studies
included in the meta-analysis.
Study characteristics of the 3 studies not included in the
meta-analysis are are presented (Extended data). From these 3 studies,
there were 4 eligible comparisons. One study reported two comparisons
(Greene & Petruzzello, 2022).
| Crombie2021 |
2021 |
38 |
exercise + extinction learning |
attention control + extinction learning |
yes |
aerobic |
moderate |
3 days |
USA |
| Greene2022a |
2022 |
24 |
exercise only |
attention control |
no |
anaerobic |
high |
130 min |
USA |
| Greene2022b |
2022 |
NA |
exercise only |
attention control |
no |
aerobic |
moderate |
130 min |
USA |
| Powers2015 |
2015 |
9 |
exercise + therapy |
therapy alone |
yes |
aerobic |
moderate |
12 weeks |
USA |
Aerobic exercise = physical performance behaviour pattern that
increases heart rate and respiration while using large muscle groups
repetitively and rhythmically; anaerobic exercise = physical performance
behaviour pattern that is performed in short intense bursts with limited
oxygen intake; USA = United States of America.
Table 3: Study characteristics of the 3 studies not
included in the meta-analysis.
Secondary outcomes
Treatment Dropout
Post-intervention (weeks)
8 studies provided data for treatment dropout, and contributed 9
effect measures to the treatment dropout meta-analysis. The forest plot
for the risk of treatment dropout presented in Figure 10.

Figure 10: Meta-analysis of the dropout rates
between the intervention and control groups
No evidence of a difference in treatment dropout between exercise and
comparison groups (RR = 1.28, 95% CI 0.67 to 2.45) was found and there
was large heterogeneity, as shown by the prediction interval (0.16 to
10.15).
Functional impairment
Two studies examined the effects of exercise on functional impairment
post-intervention (Nordbrandt et al., 2020; Voorendonk et al., 2023).
Nordbrandt et al., 2020 compared treatment as usual (TAU) which
constituted of psychotherapy in the form of CBT and acceptance and
commitment therapy (n = 104) – with TAU with basic body awareness
therapy (n = 105), and exercise plus TAU (n = 109). They did not find
any evidence that exercise +TAU is more effective than either TAU or TAU
+basic body awareness therapy. Voorendonk et al. compared an 8-day
intensive trauma-focused therapy (TFT) programme with (n = 59) and
without exercise (n = 60). The intensive TFT programme consisted of
daily prolonged exposure, EMDR therapy and psychoeducation complemented
with physical activities for the exercise group and controlled mixtures
of creative tasks for the control group. They did not find any evidence
that exercise is more effective than the control in improving quality of
life (Voorendonk et al., 2023).
PTSD symptom clusters
Two of the 11 studies examined the effects of exercise on PTSD
symptom clusters, namely avoidance, re-experiencing, hyperarousal, as
well as negative cognitions and mood (Whitworth et al., 2019a; Whitworth
et al., 2019b). One study reported significantly lower levels of
avoidance symptoms (Cohens’ d = 1.26; 95% CI [0.39, 2.14]) and
hyperarousal symptoms (d = 0.90; 95% CI [0.06, 1.74]) in the exercise
group (n = 15) relative to the control group (n = 15) post-intervention
(Whitworth et al., 2019a).While intrusion (d = 0.67; 95% CI [−0.15,
1.49]) and mood and cognitive symptoms (d = 0.34; 95% CI [−0.47, 1.14],)
did not differ between the exercise group (n = 15) and the control group
(n = 15) post-intervention (Whitworth et al., 2019a). The other study
found no significant between-group differences (p>0.05) between the
exercise (n = 9) and comparison (n = 10) groups for intrusion (d= -0.65
vs d = -1.25), avoidance (d = -0.95 vs d = -0.92) mood and cognitive
symptoms (d= -0.73 vs d = -0.70) , and hyperarousal symptoms (d= -0.43
vs d = -0.59)(Whitworth et al., 2019b).
Loss of PTSD diagnosis
Only one study reported data on loss of PTSD diagnosis
post-intervention (Voorendonk et al., 2023). Loss of diagnosis was high
in both the exercise and comparison groups. Findings based on the CAPS-5
showed that the loss of PTSD diagnosis post-intervention did not differ
between the exercise and the control groups (80.0% versus 82.7%); X2[1]
= 0.13, p = 0.72).
Mediators of the effect of exercise on PTSD-related symptoms
Three studies examined putative mediators of exercise, but the
available data was insufficient to carry out a synthesis (Crombie et
al., 2021a; Powers et al., 2015; Whitworth et al., 2019a). In Crombie et
al. 35 participants completed a 3-day fear acquisition (day 1),
extinction (day 2), and extinction recall (day 3) protocol. Each
participant was randomized to complete either intervention
(moderate-intensity aerobic exercise) or a light-intensity control
condition following extinction training on day 2. Blood samples were
obtained before and after intervention or control condition. protocol
involving fear acquisition, extinction, and recall. They examined
whether the effect of exercise on threat expectancy ratings during the
extinction recall phase was mediated by brain-derived neurotrophic
factor (BDNF), anandamide (AEA), 2-arachidonoylglycerol (2-AG), and
homovanillic acid (HVA) (Crombie et al., 2021a). Threat expectancy
ratings evaluate an individual’s anticipation levels toward encountering
threatening situations. Individuals with PTSD often exhibit elevated
ratings. Decreasing these anticipations may lead to a reduction in the
severity of PTSD symptoms. For the total effect, the exercise group
exhibited lower threat expectancy ratings following reinstatement than
the comparison group (between group d = 0.75; t(33) = -2.233, p = .032).
Circulating concentrations of BDNF (95% CI for the indirect effect =
-0.941 to -0.005) and AEA (95% CI for the indirect effect= -0.623 to
-0.005) following exercise mediated the relationship between exercise
and reduced threat expectancy ratings following reinstatement. While
2-AG (95% CI for the indirect effect= -0.050 to 0.210) and HVA (95% CI
for the indirect effect = -0.190 to 0.134) did not reach statistical
significance.
Powers examined BDNF levels as a potential mediator of the
relationship between exercise and PTSD symptom severity (Powers et al.,
2015). Post-intervention, the exercise increased BDNF concentration to a
greater degree than control condition, yielding a significantly large
(>0.8) between group effect size (d = 1.08). Likewise, exercise group
had a significantly greater reduction in PTSD symptom than the control
conduction, yielding a very large between group effect size (d = 2.65).
These findings suggest that BDNF levels might mediate the relationship
between exercise and PTSD symptom reduction.
Whitworth et al. examined whether exercise is associated with changes
in cognitive appraisal, perceived exertion, affect, arousal, and
distress in a sample of 22 adults and whether these changes impact on
PTSD symptoms (Whitworth et al., 2019a). They found changes in the
perception of the resistance training sessions (cognitive appraisal; b =
7.1, p = 0.02) and perceived exertion (b= -3.1, p = 0.01) mediated the
relationship between exercise and PTSD symptom severity. Affect (b =
0.82, p = 0.63), arousal (b = 2.4, p = 0.12), and distress (b = 0.18, p
= 0.17) did appear to have a mediating effect. These outcomes were
observed at the conclusion of the 3-week intervention.